Gas Tank capacity?

[joe_peters]

Every time that pump sucks air it is being damaged.

In-tank fuel pumps are lubricated by the FUEL. Running at less than 1/4 tank is going to bite you in the a**.

 

[NCjeepgirl83]

Well maybe mine has that? I know its always around 15 ish when I am done filling up so maybe it fills up a little more than 15. I have a 1996 Cherokee SE if that helps.

Yeah I have a 1999 XJ Sport and I can only ever get 16 gallons in it, even after driving around for awhile with the low fuel light on.

 

[sjx40250]

After 15 years of sucking air occasionally, I can attest to the bite. Losing power uphill on a turn without a shoulder is disconserting to say the least!

I really never thought of a solvent having lubricating properites. I have thought of the longevity of pump being designed to operate in a liquid with a given reynolds number as being valid. This goes for certain fish tank pumps as well. If they spin too fast with air, they may oscilate with a given harmonic that will distroy the bearing surfaces by deforming the diameter over time. Kind of like a wheel that is out of balance.

 

[heyhar]

After 15 years of sucking air occasionally, I can attest to the bite. Losing power uphill on a turn without a shoulder is disconcerting to say the least!

I really never thought of a solvent having lubricating properites. I have thought of the longevity of pump being designed to operate in a liquid with a given reynolds number as being valid. This goes for certain fish tank pumps as well. If they spin too fast with air, they may oscilate with a given harmonic that will destroy the bearing surfaces by deforming the diameter over time. Kind of like a wheel that is out of balance.

Don't forget that the little electric motor in the pump needs to be immersed in the gasoline to cool it as well, and running the level too low leaves it above the cool liquid. The pump is liquid cooled, like the engine, and you wouldn't intentionally let the radiator run dry, would you?

Inside the tank is a chamber in which the pump/sending unit sits. It is a round cylinder, with a slot down one side, to let the float arm extend out into the main part of the tank, and also act as a baffle, to keep the liquid from sloshing away from the pickup point.

I like to think of the gauge warning light as 'hey buddy, I'm hungry NOW', and not let it be on too long. None of our vehicles are new or even middle-age anymore. Each one is getting cranky going into old age. But, for the most part, they're aging rather gracefully, so give 'em what they're askin' you for. Instead of seeing the light come on, fill it before that happens.

 

[Fastdemise]

I know with my 01 I would love to be able to throw 20gal in it just so I know I'll last a solid week with all the driving I do. Back when gas was $4+ I've had it run completely dry on me and still only 16gal to fill. I'll have to look into the vent tube for fouling or damage.

 

[kastein]

Another thing to check is that a lot of fuel pumps are a little overzealous on the top-off/overflow prevention. I find that some pumps are so finicky I have to restart them half a dozen times. Usually holding the bottom of the pump handle spun about 20 degrees toward the front of the XJ keeps them pumping till the overflow sensor is actually right. This can affect your tank capacity measurement/mileage calcs greatly, of course.

 

[joe_peters]

Oregon is a "no self-serve" state.

Our beloved (can you feel the sarcasm?) Gov has determined that "topping off" is bad for the environment, and that you should simply get off the highway and sit idling (yes, idling where pollution is at its highest) in a line waiting to re-fuel.

FIPS--Freakin' Idiot Pseudo Science is costing us more and polluting the planet more every day. What would you call Al Gore and 1000 of his supporters at the bottom of the ocean? Not enough is what I would call it.

 

[clean96XJ]

When i changed my gauge cluster from idiot lights to regular gauges, my gas gauge recalibrated itself. I used to run the old fuel gauge below "E". Then, it was empty.

With the new gauges, once the light comes on I figure +4 to +5 gallons left. Never wait to hit "E". Ask me how I know!